My pigeon seems to have phlegm in its throat when it breathes. What is the disease and how to treat it? thank you

There are two possibilities, one is trichomonas and the other is tracheitis. First, trichomonas: Young pigeons are the most susceptible to infection. If the young pigeons are infected soon after hatching, the first symptom will appear after 10- 14 days, and the excrement will become thin and sour. Pigeons stagnate and continue to sing. Young pigeons are fed less, and yellow spots or caseous nodules may appear in the throat and back of esophagus of young pigeons. When this parasite successfully reaches the host's liver, it will cause yellow ulcer lesions in the liver tissue, thus destroying the liver tissue and leading to death. Adult pigeons may also be harmed by trichomonas, but the degree of harm is much lighter than that of young pigeons. It will make the sick pigeon's throat inflamed, and in severe cases, the pigeon will be accompanied by "gurgling" when breathing. Sick pigeons generally have inverted feathers, increased drinking water and watery mucus diarrhea. Trichomonas is a parasite in the body and a protozoan. This disease can attack many wild birds, but only when it spreads among pigeons can it cause Trichomonas pigeon infection. This parasite is different from coccidia. Only living bugs can spread it. Theoretically, the way of infection is fighting and kissing during coitus. However, in fact, the main route of infection is the vomiting of pigeons. When pigeons are infected by trichomonas, trichomonas can feed on the swallow in pigeon milk and pigeon food, and infect young pigeons through pigeon milk or swallow used to feed young pigeons. Trichomonas can also be passed from one parent pigeon to another. After the young pigeons became independent, the drinking fountain they used became the main way to infect trichomonas. Healthy pigeons suffer from drinking the water that sick pigeons have drunk. Although trichomonas can't breed in water, they can survive in water. The dirtier the water, the better their chances of survival. The main treatment method is to feed four tablets of metronidazole with 1kg water, or 1/4 tablets, which can control the development of the disease within one week, or add a small amount of11500 iodine solution or11500 copper sulfate solution to drinking water. Pigeons are sick for a long or short time, and the degree of illness is also heavy or light. Initially, when the mucous membrane of the nasal cavity or respiratory system is inflamed, it shows a dry nasal cold, nose and eyes appear, and the wax film is dark and moist. Pigeons often scratch their heads and noses violently, and their noses are blocked and sneezed, and their throats are red, which will affect their trachea and even their airbags and lungs, making pigeons cough and giggle. The secretion in the mouth is increased and sticky, and the mouth suddenly opens and closes, and it is very difficult to breathe in the worst case. If this is the case, first isolate, wipe the mucus in the mouth with iodine spray, and take antibiotics and some anti-inflammatory drugs appropriately, and you will be fine. By comparison, take the medicine after the diagnosis.